According to sources close to neowin and Bink, Windows Server 2003 Build 3787 crashed last night - meaning it's now not in escrow. The Windows Server 2003 team have fixed the bug which caused the crash which at the moment is unknown and have declared build 3788 as the new escrow build.
The only difference this makes to the RTM date is that it's almost certain it will be at the 28th of March now due to last nights crash. Otherwise we may have seen it today.
If there are any more problems with build 3788 then this may be a problem for the Official release date which is still set as April 24th. Lets hope Build 3788 is gold ;)
News source: Bink